Heathkit hw-101 drifting problem
 

My HW-101 seems to jump frequencies up or down 3 to 5 khz both on
transmit and receive, I understand about a drifting problem during warm
up but the sudden shift in frequency even after a couple of hours of
use and have noticed that the power out is also never stable. Any ideas
on a fix or comments appreciated.

Gil

One drop of Cramolin in each the rear and front bearing of the VFO variable
tuning cap.

Possible bad cap in VFO circuit.

Most likely a candidate for an ebay sale.



"gil" wrote in message
ups.com...
My HW-101 seems to jump frequencies up or down 3 to 5 khz both on
transmit and receive, I understand about a drifting problem during warm
up but the sudden shift in frequency even after a couple of hours of
use and have noticed that the power out is also never stable. Any ideas
on a fix or comments appreciated.

Gil

I'd guess that an oscillator (either VFO or crystal, but more likely
crystal) is
unstable. If an oscillator output level is changing that could explain the
change in output
power. The HW-series had problems with resistors in the tube B+ circuits
dissipating a bit of power and changing values. To troubleshoot, verify the
signal
levels and correct frequency of all the oscillators, and measure the B+ on
all the tubes. Be careful measuring the B+, it's awful easy to get a nasty
shock;
use the one-hand in your pocket at all times approach.




"gil" wrote in message
ups.com...
My HW-101 seems to jump frequencies up or down 3 to 5 khz both on
transmit and receive, I understand about a drifting problem during warm
up but the sudden shift in frequency even after a couple of hours of
use and have noticed that the power out is also never stable. Any ideas
on a fix or comments appreciated.

Gil